Mechanical locking system for building panels

ABSTRACT

Panels are shown, which are provided with a mechanical locking system including a separate and flexible tongue allowing connection with a snap action. An outer edge part of the separate flexible tongue includes a guiding protrusion that facilitates easy disassembly of the panels and that is deformed during locking and/or unlocking.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/308,872, filed on Nov. 4, 2016, which is a U.S. National Stage ofInternational Application No. PCT/SE2015/050518, filed on May 8, 2015,which claims the benefit of Swedish Application No. 1400231-5, filed onMay 9, 2014. The entire contents of each of U.S. application Ser. No.15/308,872, International Application No. PCT/SE2015/050518, and SwedishApplication No. 1400231-5 are hereby incorporated herein by reference intheir entirety.

TECHNICAL FIELD

The disclosure relates to the field of mechanical locking systems forbuilding panels, especially furniture components with mechanical lockingsystems, which are intended to lock perpendicularly or in parallel toeach other.

FIELD OF APPLICATION

Embodiments of the present invention are particularly suitable for usein furniture components, which are preferably formed of sheet shapedpanels and which are joined mechanically with a locking systemintegrated with the panel, i.e. mounted at the factory, The followingdescription of known technology, problems of known systems and objectsand features of the invention will therefore, as a non-restrictiveexample, be aimed above all at this field of application and inparticular at furniture components formed as rectangular or squarepanels intended to be mechanically joined on one pair of opposite edgesperpendicularly or parallel to other adjacent panels.

It should be emphasised that the invention can be applied to any type ofsheet shaped panel such as for example wood based HDF, particle boardand plywood, plastic sheet shaped materials, mineral fibre and metalbased materials, stone and ceramics and similar. It may be used toassemble and disassemble furniture components, floor panels and elementsfor packaging boxes and similar. It may also be used to lock and unlockcomponents, which for example have a cylinder form such as table legs.

BACKGROUND

Furniture such as kitchen cabinets, bookshelves, drawers, tables andsimilar are generally supplied as flat components in order to savetransportation costs. The customer must assemble them. Several methodsare used to assemble such furniture components for example glue, spikes,screws and similar. Snapping connections comprising plastic componentsare widely used to connect for example drawers. It is an advantage ifassembled furniture components may be disassembled partly or completelyagain in a simple way. Mistakes during assembly may be corrected andfurniture may be dissembled again to flat components in connection withtransportation from one apartment to another. A simple and easydisassembly is an advantage even in the case when furniture componentsare factory assembled.

Known Technology and Problems Thereof

It is known from WO 2012/154113 that furniture components may be lockedmechanically with a perpendicular snap action. FIG. 1a shows a first 1and a second 2 panel. The first panel 1 comprises a groove 6, formed inthe panel core 7. An insertion groove 4 formed in one of the groovewalls comprises a flexible tongue 3 that locks into a tongue groove 5when an edge of the second panel 2 is displaced into the groove 6. FIG.1b shows a known flexible bristle tongue 3, which is used to connectfloor panels. Such a tongue is also used to connect furniturecomponents. The tongue 3 comprises flexible protrusions 8 that bend inthe length direction of the tongue and that displace the tongue in theinsertion groove 4 during the snap action. FIG. 1b shows the tongue 3 inthe outer locked position.

FIGS. 1c and 1d show that the locking system may be disassembled. A rodshaped stick 9 is inserted into the tongue groove 3 sideways. Theflexible tongue 3 is pushed back into the insertion groove 4 and thesecond panel 2 may be released from the first panel 1.

The main problem with such disassembly is that the rod shaped stick 9must be turned in a correct position and must be inserted precisely intothe tongue groove 5. A disassembly is not possible if the rod shapedstick is inserted into the insertion groove 4.

SUMMARY

A basic objective of embodiments of the present invention is to simplifydisassembly of panels that are locked perpendicularly to each other witha flexible tongue.

The above objects of embodiments of the invention are achieved wholly orpartly by a mechanical locking system and panels, according to theindependent claims that provide a stronger and easier locking andunlocking. Embodiments of the invention are evident from the dependentclaims and from the description and drawings.

A first aspect of the invention is a set of panels comprising a firstand a second panel. A panel edge of the second panel is insertable intoa core groove of the first panel to obtain a mechanical connectionbetween the first and the second panel. The panel edge is insertableinto the core groove by an essentially linear relative displacement ofthe first and second panel when the first and second panel are arrangedessentially perpendicularly to each other. The panel edge comprising aseparate and flexible tongue and the core groove comprising a tonguegroove, or the panel edge comprising a tongue groove and the core groovecomprising a separate and flexible tongue. The separate and flexibletongue is insertable into the tongue groove for connecting the panels toeach other in a first direction, which is perpendicular to a main plane(MP-1) of the first panel. The panel edge of the second panel isconfigured to cooperate with the core groove of the first panel forconnecting the panels to each other in a second direction, which isperpendicular to a main plane (MP-2) of the second panel. A longitudinaldirection of the separate and flexible tongue extends parallel with thepanel edge and/or core groove. The separate and flexible tongue isarranged in an insertion groove and the separate and flexible tonguebeing displaceable inwardly towards a bottom of the insertion grove andoutwardly into the tongue groove during a locking of the first andsecond panel. The separate and flexible tongue comprises a guidingprotrusion at a short edge of the separate and flexible tongue and theguiding protrusion is configured such that its shape changes during thelocking and/or unlocking of the first and second panel.

By means of the inventive concept, the panels may be disassembled in animproved and simple manner.

Preferably, the panels in the set of panels are essentially formed asparallelepipeds or, more specifically, as rectangular parallelepipeds.

Each of the panels, in particular the first and the second panel, maycomprise a lower side and an upper side. Preferably, the lower and uppersides are shaped as rectangles or squares and are planar. The lower sideand the upper side may be parallel. In one example, the panel has auniform thickness. In another example, the panel has a non-uniformthickness. In yet another example, the panel comprises two or moresections, each having a uniform thickness. The lower side and the upperside of the panel may be parallel with the main plane of the panel. Inparticular, the main plane of the panel may coincide with the lower orthe upper side of the panel. Moreover, each panel may comprise sideedges which may connect the upper and lower sides. In the case of apanel formed as a parallelepiped, there may be two pairs of side edges.Preferably, at least portions of the two side edges in each pair of sideedges are parallel.

In one example, a density of the panel is uniform. In another example,the density of the panel is higher closer to the upper and/or lowersides than in a center part of the panel.

The first direction may be parallel to the main plane of the secondpanel. Moreover, the second direction may be parallel to the main planeof the first panel.

The panel edge of a panel may comprise at least a portion of a side edgeof the panel. Additionally, the panel edge may comprise a portion of thelower side and a portion of the upper side of the panel close to theside edge. A shape of the panel edge may substantially correspond to ashape of the core groove. Thereby, the second panel may engage with thefirst panel in a tightly fit manner. In particular, the panel edge andthe core groove may be essentially U-shaped. Optionally, corners of thepanel edge and/or the core groove may be bevelled.

By a short edge of the separate and flexible tongue is here meant anedge of the tongue in a longitudinal direction of the separate andflexible tongue.

The separate and flexible tongue may comprise an outer edge part that isformed as a guiding protrusion.

The guiding protrusion may be in contact with an inner part of theinsertion groove during the locking.

In particular, in a locked position of the first and the second panel,the guiding protrusion may be in contact with the inner part of theinsertion groove.

Alternatively, there may be a space between the inner part of theinsertion groove and the guiding protrusion in a locked position of thefirst and the second panel. The space is preferably smaller than thedisplacement of the separate and flexible tongue during locking along adirection towards the inner part of the insertion groove.

The guiding protrusion may be curve shaped and configured to guide a rodshaped tool into the tongue groove when the rod shaped tool is insertedinto the insertion groove. By curve shaped is here meant that at least aportion of the guiding protrusion is shaped as a curve. The curve mayhave a non-zero curvature. In particular, as seen from a top view, anouter side of the guiding protrusion may be shaped as a curve. Thecurvature is preferably such that an angle formed between a tangentialdirection of the outer side of the guiding protrusion and a longitudinaldirection of the rod shaped tool is acute. In particular, the angle maybe between 1° and 89°. Since the guiding protrusion is curve shaped, theacute angle may vary along the guiding protrusion in a direction towardsa tip of the guiding protrusion. For example, the acute angle mayincrease towards the tip of the guiding protrusion.

According to an alternative embodiment, the guiding protrusion comprisesat least one straight portion. As seen from a top view, each straightportion may be inclined with respect to a longitudinal direction of thetongue. In one example, the guiding protrusion comprises one straightportion. In another example, the guiding protrusion comprises at leasttwo straight portions. In the latter example, the straight portions arepreferably juxtaposed. The angle with respect to the longitudinaldirection of the tongue may be different between the different straightportions. For example, the angle may increase by each straight portiontowards the tip of the guiding protrusion.

In one example, a cross section of the guiding protrusion along adirection towards the tip of the guiding protrusion is constant. Inanother example, the cross section of the guiding protrusion istapering. Moreover, in non-limiting examples, the cross section of theguiding protrusion along a direction towards its tip may be shaped as acircle, an oval, a polygon, a rectangle, a square, or a triangle.

The guiding protrusion may be flexible. More generally, at leastportions of the guiding protrusion may be flexible.

The rod shaped tool may comprise an essentially round cross section. Inparticular, the cross-section may be shaped as a circle or an oval. Byhaving a rotationally symmetric cross-section, such as a circle, theprecise orientation of the rod shaped tool when inserting it into theinsertion groove may become immaterial, which may further simplify thedisassembly of the panels.

The separate and flexible tongue may comprise several flexibleprotrusions extending in the length direction of the tongue.

The insertion groove may be formed in the core groove of the firstpanel.

When the panel edge comprises the tongue groove and the core groovecomprises the separate and flexible tongue, the tongue groove may bearranged in the lower side or in the upper side of the second panel. Inparticular, the tongue groove may be arranged in the lower side or inthe upper side of the second panel, close to a side edge of the secondpanel.

Moreover, when the panel edge comprises the tongue groove and the coregroove comprises the separate and flexible tongue, the insertion groovemay be formed in the core groove. The core groove may comprise two sidewalls and a bottom wall. The two side walls of the core groove may beparallel. According to one embodiment, the insertion groove may bearranged in a side wall of the core groove. A shape of at least a partof the flexible tongue may substantially correspond to a shape of theinsertion groove. In particular, the flexible tongue and the insertiongroove may be essentially U-shaped. The insertion groove may comprisetwo side walls and a bottom wall. The side walls of the insertion groovemay be parallel. In a first example, the bottom wall of the insertiongroove is planar. In a second example, the bottom wall of the insertiongroove is rounded. The insertion groove may be inclined with respect tothe lower side and/or the upper side of the first panel. In anon-limiting example, the angle between a side wall of the insertiongroove and the lower side and/or the upper side of the first panel maybe between 5° and 45°.

The tongue groove may comprise two side walls and a bottom wall. Theside walls of the tongue groove may be parallel. In a first example, thebottom wall of the tongue groove is planar. In a second example, thebottom wall of the tongue groove is rounded. The tongue groove may beinclined with respect to the lower side and/or the upper side of thesecond panel. In a non-limiting example, the angle between a side wallof the tongue groove and the lower side and/or the upper side of thesecond panel may be between 45° and 85°. The inclination of the tonguegroove may correspond to an inclination of the insertion groove so thatin a connected state of the first and second panel, parallel side wallsof the tongue groove and parallel side walls of the insertion groove areessentially aligned with each other.

A second aspect of the invention is a locking system for locking ofpanels comprising a first and a second panel. A panel edge of the secondpanel is insertable into a core groove of the first panel to obtain amechanical connection between the first and the second panel. The paneledge is insertable into the core groove by an essentially linearrelative displacement of the first and second panel when the first andsecond panel are arranged essentially perpendicularly to each other. Thelocking system comprises a separate and flexible tongue arranged in aninsertion groove which is formed in the core groove and a tongue grooveat the panel edge. The tongue groove is adapted to accommodate a part ofthe separate and flexible tongue. The separate and flexible tonguecomprises a guiding protrusion at a short edge of the separate andflexible tongue. The guiding protrusion is configured such that itsshape changes when a rod shaped tool is inserted into at least a part ofthe tongue groove.

The rod shaped tool may comprise an essentially round cross section.

The invention provides the advantages that a rod shaped tool may beinserted sideways into the insertion groove that generally is largerthan the tongue groove and the tool will be automatically guided by theguiding protrusion into the tongue groove. The rod shaped tool may havea simple round cross section and a precise orientation of the toolduring insertion into the groove may be avoided. This facilitates aneasy and simple disassembly of locked panels.

According to a third aspect of the invention, there is provided a set ofpanels comprising a first and a second panel. A panel edge of the secondpanel is insertable into a core groove of the first panel to obtain amechanical connection between the first and the second panel, the paneledge being insertable into the core groove by an essentially linearrelative displacement of the first and second panel when the first andsecond panel are arranged essentially perpendicularly to each other.Moreover, the panel edge comprises a separate and flexible tongue andthe core groove comprises a tongue groove, wherein the separate andflexible tongue is insertable into the tongue groove for connecting thepanels to each other in a first direction, which is perpendicular to amain plane of the first panel. The panel edge of the second panel isconfigured to cooperate with the core groove of the first panel forconnecting the panels to each other in a second direction, which isperpendicular to a main plane of the second panel. A longitudinaldirection of the separate and flexible tongue extends parallel with thepanel edge and/or core groove. The separate and flexible tongue isarranged in an insertion groove and is displaceable inwardly towards abottom of the insertion groove and outwardly into the tongue grooveduring a locking of the first and second panel. An engagement portion ofthe core groove is arranged to engage with the separate and flexibletongue during locking of the first and second panel for displacing theseparate and flexible tongue inwardly towards the bottom of theinsertion groove, wherein the engagement portion is bevelled.

The bevelled engagement portion may be an upper bevelled engagementportion, provided close to, or at, an upper or lower side of the secondpanel.

The bevelled engagement portion may be provided in an upper part of thefirst panel, the upper part having a higher density than a center partof the first panel.

The bevelled engagement portion may be provided between a side wall ofthe core groove and a lower or upper side of the first panel. Inparticular, the bevelled engagement portion may join the side wall ofthe core groove and the upper or lower side of the first panel.

The second panel may comprise an overlapping portion, which engages withthe bevelled engagement portion in a locked position of the first andsecond panel.

A thickness of the second panel may be smaller at the panel edge than ina visible part of the second panel which is visible in a locked positionof the first and the second panel.

A distance between a lower edge side and a parallel upper edge side ofthe panel edge may be smaller than a distance between a lower side and aparallel upper side, the lower and upper edge sides being located closerto a side edge of the second panel than the lower and upper sides.

The insertion groove may be provided in the lower edge side or in theupper edge side of the panel edge. Alternatively, the insertion groovemay be provided in the lower side or in the upper side of the secondpanel.

According to a fourth aspect of the invention, there is provided a setof panels comprising a first and a second panel. A panel edge of thesecond panel is insertable into a core groove of the first panel toobtain a mechanical connection between the first and the second panel,and the panel edge is insertable into the core groove by an essentiallylinear relative displacement of the first and second panel when thefirst and second panel are arranged essentially in the same plane MP-1.Moreover, the panel edge comprises a separate and flexible tongue andthe core groove comprises a tongue groove, or the panel edge comprises atongue groove and the core groove comprises a separate and flexibletongue. The separate and flexible tongue is insertable into the tonguegroove for connecting the panels to each other in a first direction,which is parallel to a main plane of the first panel. The panel edge ofthe second panel is configured to cooperate with the core groove of thefirst panel for connecting the panels to each other in a seconddirection, which is perpendicular to the main plane of the panels. Alongitudinal direction of the separate and flexible tongue extendsparallel with the panel edge and/or core groove. Moreover, the separateand flexible tongue is arranged in an insertion groove and isdisplaceable inwardly towards a bottom of the insertion groove andoutwardly into the tongue groove during a locking of the first andsecond panel. The separate and flexible tongue comprises a guidingprotrusion at a short edge of the separate and flexible tongue, and theguiding protrusion is configured such that its shape changes during thelocking and/or unlocking of the first and second panel.

The guiding protrusion may be further configured to be in contact withan inner part of the insertion groove during the locking.

The guiding protrusion may be curve shaped and configured to guide a rodshaped tool into the tongue groove when the rod shaped tool is insertedinto the insertion groove.

The rod shaped tool may comprise an essentially round cross section.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a-1d illustrate known technology;

FIGS. 2a-2d illustrate disassembly of locked panels according to anembodiment;

FIGS. 3a-3d illustrate embodiments of separate flexible tongues;

FIGS. 4a-4c illustrate assembly and disassembly of panels according toan alternative embodiment;

FIGS. 5a-5d illustrate assembly and disassembly of panels located in thesame main plane according to an embodiment.

DESCRIPTION OF EMBODIMENTS

To facilitate understanding, several locking systems in the figures areshown schematically. It should be emphasised that improved or differentfunctions can be achieved using combinations of the preferredembodiments.

FIGS. 2a-d illustrate a first panel 1 and a second panel 2 which areconnected to each other in accordance with an embodiment. The firstpanel 1 comprises a core groove 6 which is arranged in an upper side 1 bof the first panel 1. The core groove 6 comprises two opposing sidewalls 6 a, 6 b and a bottom wall 6 c. The opposing side walls 6 a, 6 bare parallel. The second panel 2 comprises a panel edge 12 which in alocked position of the panels 1, 2 is arranged in the core groove 6.More specifically, a portion of a lower side 2 a, a portion of an upperside 2 b, and a side edge 2 c of the second panel 2 are arranged in thecore groove 6. The panels 1, 2 may be locked to each other by means of aseparate and flexible tongue 3.

FIG. 2a shows a top view of the flexible tongue 3 in a locked position.A part of the flexible tongue 3 comprising flexible protrusions 8 islocated in an insertion groove 4. An opposite part is located in thetongue groove 5 according to known technology. The flexible tongue 3comprises an outer edge part 3 a that is formed as a guiding protrusion10 that automatically guides a rod shaped tool 9 into a tongue groove 5when the tool 9 is inserted sideways into the insertion groove 4. Theguiding protrusion 10 is arranged at a short edge of the tongue 3. It isunderstood that there may be a corresponding guiding protrusion 10arranged at the other short edge of the tongue 3 (not shown).

FIG. 2b shows that the flexible guiding protrusion is deformed when therod shaped tool 9 is displaced sideways parallel to the length directionof the tongue 3 such that the tongue 3 is pressed into the insertiongroove 4. It is an advantage if the flexible guiding protrusion 10 is incontact with an inner part of the insertion groove 4 during locking andwhen the tongue is pressed into the insertion groove. The guidingprotrusion 10 is preferably flexible and is preferably also formed as acurved edge part.

FIG. 2c shows a side view of the locking system. According to thepresent embodiment, a main plane MP-1 of the first panel 1 coincideswith the upper side 1 b of the first panel 1. Moreover, a main planeMP-2 of the second panel 2 coincides with the lower side 2 a of thefirst panel 2, which is situated to the left, as shown in FIG. 2c . Therod shaped tool 9 preferably comprises an essentially round crosssection. According to the present embodiment, the cross section of therod shaped tool 9 is circular. Moreover, a width of the rod shaped tool9 corresponds to a width of the tongue groove 5 between two parallelside walls 5 a, 5 b thereof. According to the present embodiment, abottom wall 5 c of the tongue groove 5, connecting the two side walls,is rounded. The curvature of the rounded bottom wall 5 c substantiallycorresponds to the curvature of the rod shaped tool 9. Thereby, animproved guiding of the rod shaped tool 9 may be provided. In thepresent embodiment, the rod shaped tool 9 is adapted to be fitted insidethe tongue groove 5 so that essentially no portion of the rod shapedtool 9 extends outside the lower side 2 a of the second panel 2.Thereby, the panels 1, 2 may be easily disassembled, since the rodshaped tool 9 may be fitted inside the tongue groove 5 while the tongue3 is displaced into the insertion groove 4, thereby releasing themechanical connection between the first 1 and the second panel 2. FIG.2d shows disassembly of the first 1 and the second panel 2 according tothe present embodiment.

It is clear that other shapes of the rod shaped tool 9 and the tonguegroove 5 are equally conceivable. For example, the cross-section of therod shaped tool 9 may be shaped as a polygon, a rectangle, a square, anoval, a triangle or a star. Additionally, according to alternativeembodiments, the shape of the bottom wall may not correspond to theshape of the rod shaped tool 9. For example, the cross-section of therod shaped tool 9 may be circular and the cross-section of the tonguegroove 5 may be U-shaped, for example comprising a planar bottom wall.

The insertion groove 4 may also be formed in the second panel 2 and thetongue groove 5 may be formed in the core groove 6 of the first panel 1.This will be described in more detail below.

The above-described embodiment provides the advantages that theinsertion of the tool 9 may be made into the whole cross sectioncomprising the insertion groove 4 and the tongue grooves 5. A symmetrictool cross section may be used that eliminates a precise orientation ofthe tool 9 prior to insertion into the grooves.

The guiding of the rod shaped tool 9 is illustrated in FIG. 2a and FIG.2c . The broken lines illustrate the position of the rod shaped tool 9when inserted into the insertion groove 4 and the arrows indicate thatthe rod shaped tool 9 is guided into the tongue groove 5 in the showndirection.

FIG. 3a shows a tongue blank 11 comprising several thermoplasticinjection-moulded flexible tongues 3. The tongues are preferablyseparated from the blank 11 at a separation portion S located inwardlyand at a distance from the outer edge of the tongue 3.

FIG. 3b shows that the guiding protrusion 10 may replace one of theflexible protrusions 8 such that all flexible protrusions 8 are locatedalong the tongue in the length direction of the tongue and spaced in thelength direction from the guiding protrusion 10.

FIG. 3c shows that the principles of the invention may be used toimprove disassembly when other types of tongues are used for exampleflexible tongues comprising a snap tab 13 at the outer part. The lockingsystem comprising a flexible snap tab 13 may be formed such that a tool9 with an essentially round cross section may be used to release thefirst 1 and the second 2 panels.

FIG. 3d shows that such tongue 3 comprising a snap tab 13 may comprise asymmetric cross section in inner parts and an edge portion that may becut or formed to a wedge shaped edge part 14. The flexible tongue maycomprise a flexible snap tab and an asymmetric cross section along itslength direction.

In particular, the flexible tongue 3 may be tapering towards an edge ofthe flexible tongue 3 in a longitudinal direction. Thereby, an area ofthe cross section of the flexible tongue 3 may decrease towards theedge. Additionally, a maximal horizontal distance from an inner part ofthe cross section to an outer part of the cross section may decreasetowards the edge. Here, the horizontal distance is measured in adirection along which the flexible tongue 3 is adapted to contract andexpand. For example, the horizontal distance may be measured in adirection along which the flexible snap tab 13 is adapted to contractand expand. As shown in the embodiment according to FIG. 3d , the crosssection of the flexible snap tab 13 decreases towards the edge. Aportion 13 a of the flexible snap tab 13 has been cut out from theflexible tongue 3 for providing the tapering edge.

Next, an alternative embodiment will be described with respect to FIGS.4a-c . FIGS. 4a and 4b show a side view of a first panel 1 and a secondpanel 2 which are being assembled. It is understood that, in FIGS. 4a-c, the first panel 1 extends horizontally and that the second panel 2extends vertically and that only a connecting region of the first 1 andsecond 2 panel is shown. The first 1 and second 2 panels are arrangedessentially perpendicularly to each other.

According to the present embodiment, the first panel 1 comprises threeparts: an upper part 30, a center part 32, and a lower part 34. Theupper part 30 and the lower part 34 are located close to the upper 1 band lower 1 a sides, respectively, and have a higher density than thecenter part 32.

The core groove 6 comprises two opposing side walls 6 a, 6 b and abottom wall 6 c. The core groove 6 comprises a tongue groove 5. Thetongue groove 5 is provided in the side wall 6 a of the tongue groove 5.Thus, the tongue groove 5 is provided in a left part 21 a of the firstpanel 1 which is located to the left of core groove 6. Moreover, thetongue groove 5 comprises two parallel side walls 5 a, 5 b and a bottomwall 5 c. As seen from the side view in FIGS. 4a-c , a linear extensionE of the lower side wall 5 a is located at or above a right part 21 b ofthe first panel 1, which is located to the right of core groove 6.Thereby, a tool, such as a cutting tool, may easily provide the tonguegroove 5 by means of a linear displacement of the tool.

An engagement portion 20 of the core groove 6 is bevelled. The bevelledengagement portion 20 is provided between an upper part of the side wall6 a and the upper side 1 b of the first panel 1, thereby joining them.Alternatively, the engagement portion 20 of the core groove 6 may berounded off.

Moreover, the panel edge 12 of the second panel 2 has a smallerthickness than an inner part of the second panel 2, wherein the innerpart is located farther from a side edge 2 c of the second panel 2 thanthe panel edge 12. More specifically, the panel edge 12 comprises alower edge side 22 a and an upper side edge 22 b which are parallel toeach other and are located closer to the side edge 2 c of the secondpanel 2 than a lower side 2 a and an upper side 2 b of the second panel2. As displayed in FIG. 4c , the distance d₁ between the lower edge side22 a and the upper side edge 22 b is smaller than the distance d₂between the lower side 2 a and the upper side 2 b.

The lower edge side 22 a is joined to the lower side 2 a by means of anoverlapping portion 24. According to the present embodiment, there is acorresponding upper edge side 22 b which is joined to the upper side 2 bof the second panel 2 by means of an overlapping portion 25. By means ofthe overlapping portions 24, 25, which in an assembled state, or lockedposition, of the first 1 and second 2 panels engage with the bevelledengagement portion 20 and a bevelled surface 27 of the core groove 6,respectively, the panel edge 12 and/or the core groove 6 may beconcealed in an improved manner.

The panel edge 12 comprises a separate and flexible tongue 3. Theseparate and flexible tongue 3 may assume a contracted state and anexpanded state and has a tendency to assume the expanded state when noforces are acting on it. The separate and flexible tongue 3 is arrangedin an insertion groove 4 which is provided in lower edge side 22 a ofthe panel edge 12. The separate and flexible tongue 3 comprises achamfered portion 23 which is pointing downwards when the separate andflexible tongue 3 is inserted into the insertion groove 4.

When the first 1 and second 2 panels are assembled, the panel edge 12 ofthe second panel 2 is inserted into the core groove 6 of the first panel1 by a relative vertical displacement of the first 1 and second 2panels. The displacement is linear. The separate and flexible tongue 3is partly inserted into the insertion groove 4 and is further displacedinto the insertion groove 4 when the chamfered portion 23 engages withthe bevelled engagement portion 20 during the vertical displacement. Bymeans of the bevelled engagement portion 20, the chamfered portion 23engages with a smooth surface during the assembly. Thereby, thechamfered portion 23 may avoid engaging with any sharp edges duringassembly. When displaced further into the insertion groove 4, theseparate and flexible tongue 3 may become contracted. When the sidewalls 4 a, 4 b of the insertion groove 4 are aligned with the side walls5 a, 5 b of the tongue groove 5, the separate and flexible tongue 3 mayexpand and may be displaced out from the insertion groove 4 and into thetongue groove 5 for obtaining a locking of the first 1 and second 2panels in a direction which is perpendicular to the main plane MP-1 ofthe first panel.

The core groove 6 comprises an inclined portion 16 between the side wall6 a and the bottom wall 6 c as well as between the side wall 6 b and thebottom wall 6 c. Moreover, the panel edge 12 comprises a bevel 26between the lower edge side 22 a and the side edge 2 c of the secondpanel 2 and a bevel 26 between the upper edge side 22 b and the sideedge 2 c of the second panel 2. A shape of the inclined portion 16 maysubstantially correspond to a shape of the bevel 26. For example, theinclination of the inclined portion 16 and the bevel 26 may besubstantially the same. The bevels 26 may remove sharp corners betweenthe edge sides 22 a, 22 b and the side edge 2 c. Moreover, the bevels 26may guide the second panel 2 into a proper locking position.

In a locked position of the panels 1, 2, the panel edge 12 cooperateswith the core groove 6 for connecting the panels to each other in asecond direction, which is perpendicular to a main plane MP-2 of thesecond panel 2.

From FIG. 4b it is clear that the visible outer parts of the first 1 andsecond 2 panels have a uniform thickness in a locked position of thefirst 1 and second 2 panel.

It is understood that according to an alternative embodiment, the secondpanel 2 may have a uniform thickness.

FIG. 4c shows a side view of a first panel 1 and a second panel 2 whichare being disassembled. This is analogous to the disassembly describedabove in relation to FIGS. 2a-d . In particular, when disassembling, therod shaped tool 9 is inserted sideways into the insertion groove 4 andis guided into a proper position in the tongue groove 5 by means of aguiding protrusion 10 which is provided at a short edge of the separateand flexible tongue 3. When the rod shaped tool 9 is inserted into thetongue groove 5, the separate and flexible tongue 3 is displaced intoinsertion groove 4. Thereby, the second panel 2 becomes unlocked and thepanel edge 12 may be removed from the core groove 6 by a relative linearvertical displacement of the first 1 and second 2 panel.

FIGS. 5a-5d show a locking system that may be used to lock and unlock afirst 1 and a second 2 panel that, in a locked position, are located inthe same main plane MP-1. In other words, the panels are arrangedessentially in parallel with each other. Such a locking system may beused to lock two or several furniture components with, for example, alength of 0.6 m and that after locking form a part of a book shelf witha length of, for example, 1.2 or 1.8 m. An advantage of providing thistype of locking system is that smaller components are easier totransport, assemble and disassemble. It is clear than other lengths ofthe furniture components are equally conceivable. In non-limitingexamples, the length may be between 0.1 m and 1.0 m.

In the present embodiment, the first panel 1 and the second panel 2 havea uniform thickness.

The first panel 1 comprises a core groove 6 and a tongue groove 5 andthe second panel 2 comprises a panel edge 12 that is insertable into thecore groove 6 with a displacement parallel with the main plane MP-1 ofthe first and the second panel. The panel edge 12 comprises a separateand flexible tongue 3 which is provided in an insertion groove 4. In alocked position of the panels, the separate and flexible tongue 3 locksinto the tongue groove 5.

According to an alternative embodiment (not shown), the tongue groove 5may be provided in the second panel 2 and the separate and flexibletongue 3 may be provided in the first panel 1.

It is essential that the locking system is strong in order to providesufficient rigidity to the locked components. Preferably, an upper edge30 a and a lower edge 31 a of the first panel 1 and an upper edge 31 band a lower edge 31 b of the second panel 2 are in contact with eachother when the panels 1, 2 are locked.

According to the present embodiment, a side face of the panel edge 12engages with a bottom wall of the core groove 6 in a locked position ofthe first 1 and second 2 panel. This may be seen in FIG. 5c . Inaddition, in a locked position, an upper and a lower face of the paneledge 12 engage with a respective one of two opposing side walls of thecore groove 6. According to an alternative embodiment (not shown),however, the side face of the panel edge 12 may be separated from thebottom wall of the core groove 6 in a locked position of the first 1 andsecond 2 panel.

The first panel 1 comprises an engagement portion 40 which is arrangedto engage with the separate and flexible tongue 3 during locking of thefirst 1 and second 2 panel for displacing the separate and flexibletongue 3 inwardly towards the bottom of the insertion groove 4. Theengagement portion 40 is inclined with respect to the main plane MP-1 ofthe first 1 and second 2 panel. Moreover, the engagement portion 40 isbevelled at a portion 42 which is adjacent to the tongue groove 5.

FIG. 5d shows unlocking of the first 1 and second 2 panels with a rodshaped tool 9 according to the above-described methods. The separate andflexible tongue 3 comprises an outer edge part 3 a that is formed as aguiding protrusion 10 that automatically guides the rod shaped tool 9into the tongue groove 5 when the tool 9 is inserted sideways into theinsertion groove 4.

EMBODIMENTS

1. A set of panels (1,2) comprising a first (1) and a second panel (2),a panel edge (12) of the second panel (2) being insertable into a coregroove (6) of the first panel (1) to obtain a mechanical connectionbetween the first and the second panel, the panel edge (12) beinginsertable into the core groove (6) by an essentially linear relativedisplacement of the first and second panel when the first and secondpanel are arranged essentially perpendicularly to each other,

-   -   said panel edge (12) comprising a separate and flexible tongue        (3) and said core groove (6) comprising a tongue groove (5), or        said panel edge (12) comprising a tongue groove (5) and said        core groove (6) comprising a separate and flexible tongue (3),    -   wherein the separate and flexible tongue (3) is insertable into        the tongue groove (5) for connecting said panels to each other        in a first direction, which is perpendicular to a main plane        (MP-1) of the first panel,    -   wherein the panel edge (12) of the second panel (2) is        configured to cooperate with the core groove (6) of the first        panel (1) for connecting said panels to each other in a second        direction, which is perpendicular to a main plane (MP-2) of the        second panel,    -   wherein a longitudinal direction of the separate and flexible        tongue (3) extends parallel with said panel edge and/or core        groove, and    -   wherein the separate and flexible tongue (3) is arranged in an        insertion groove (4), said separate and flexible tongue (3)        being displaceable inwardly towards a bottom of the insertion        groove (4) and outwardly into the tongue groove (5) during a        locking of the first and second panel,    -   characterized in that the separate and flexible tongue (3)        comprises a guiding protrusion (10) at a short edge of the        separate and flexible tongue (3), and that the guiding        protrusion (10) is configured such that its shape changes during        the locking and/or unlocking of the first and second panel.

2. The set of panels as in embodiment 1, wherein the guiding protrusion(10) is further configured to be in contact with an inner part of theinsertion groove (4) during the locking.

3. The set of panels as in embodiment 1, wherein there is a spacebetween an inner part of the insertion groove (4) and the guidingprotrusion (10) in a locked position of the first (1) and the second (2)panel.

4. The set of panels as in any of the preceding embodiments, wherein theguiding protrusion (10) is curve shaped and configured to guide a rodshaped tool (9) into the tongue groove (5) when the rod shaped tool (9)is inserted into the insertion groove (4).

5. The set of panels as in any of the preceding embodiments, wherein therod shaped tool (9) comprises an essentially round cross section.

6. The set of panels as in any of the preceding embodiments, wherein theseparate and flexible tongue (3) comprises several flexible protrusions(8, 10) extending in the length direction of the tongue (3).

7. The set of panels as in any of the preceding embodiments, wherein,when said panel edge (12) comprises the tongue groove (5) and said coregroove (6) comprises the separate and flexible tongue (3), said tonguegroove (5) is arranged in a lower side (2 a) or in an upper side (2 b)of the second panel (2).

8. The set of panels as in any of the preceding embodiments, wherein,when said panel edge (12) comprises the tongue groove (5) and said coregroove (6) comprises the separate and flexible tongue (3), saidinsertion groove (4) is formed in said core groove (6) of the firstpanel (1).

9. The set of panels according to embodiment 8, wherein said insertiongroove (4) is arranged in a side wall (6 a) of said core groove (6).

10. A locking system for locking of panels (1, 2) comprising a first (1)and a second panel (2), wherein a panel edge (12) of the second panel(2) is insertable into a core groove (6) of the first panel (1) toobtain a mechanical connection between the first and the second panel,the panel edge (12) being insertable into the core groove (6) by anessentially linear relative displacement of the first and second panelwhen the first and second panel are arranged essentially perpendicularlyto each other, wherein the locking system comprises:

-   -   a separate and flexible tongue (3) arranged in an insertion        groove (4) which is formed in the core groove (6); and    -   a tongue groove (5) at the panel edge (12), said tongue groove        (5) being adapted to accommodate a part of the separate and        flexible tongue (3),    -   characterized in that the separate and flexible tongue (3)        comprises a guiding protrusion (10) at a short edge of the        separate and flexible tongue (3), and that the guiding        protrusion is configured such that its shape changes when a rod        shaped tool (9) is inserted into at least a part of the tongue        groove (5).

11. A locking system as in embodiment 10, wherein the rod shaped tool(9) comprises an essentially round cross section.

12. A set of panels (1,2) comprising a first (1) and a second panel (2),a panel edge (12) of the second panel (2) being insertable into a coregroove (6) of the first panel (1) to obtain a mechanical connectionbetween the first and the second panel, the panel edge (12) beinginsertable into the core groove (6) by an essentially linear relativedisplacement of the first and second panel when the first and secondpanel are arranged essentially perpendicularly to each other,

-   -   said panel edge (12) comprising a separate and flexible tongue        (3) and said core groove (6) comprising a tongue groove (5),    -   wherein the separate and flexible tongue (3) is insertable into        the tongue groove (5) for connecting said panels to each other        in a first direction, which is perpendicular to a main plane        (MP-1) of the first panel,    -   wherein the panel edge (12) of the second panel (2) is        configured to cooperate with the core groove (6) of the first        panel (1) for connecting said panels to each other in a second        direction, which is perpendicular to a main plane (MP-2) of the        second panel,    -   wherein a longitudinal direction of the separate and flexible        tongue (3) extends parallel with said panel edge and/or core        groove, and    -   wherein the separate and flexible tongue (3) is arranged in an        insertion groove (4), said separate and flexible tongue (3)        being displaceable inwardly towards a bottom of the insertion        groove (4) and outwardly into the tongue groove (5) during a        locking of the first and second panel,    -   characterized in that an engagement portion (20) of the core        groove (6) is arranged to engage with said separate and flexible        tongue (3) during locking of the first and second panel for        displacing the separate and flexible tongue (3) inwardly towards        the bottom of the insertion groove (4), wherein said engagement        portion (20) is bevelled.

13. The set of panels as in embodiment 12, wherein the bevelledengagement portion (20) is provided in an upper part (30) of the firstpanel (1), said upper part (30) having a higher density than a centerpart (32) of the first panel (1).

14. The set of panels as in embodiment 12 or 13, wherein the bevelledengagement portion (20) is provided between a side wall (6 a) of saidcore groove (6) and a lower (1 a) or upper side (1 b) of the first panel(1).

15. The set of panels as in any of embodiments 12 to 14, wherein thesecond panel (2) comprises an overlapping portion (24), which engageswith the bevelled engagement portion (20) in a locked position of thefirst (1) and second (2) panel.

16. The set of panels as in any of embodiments 12 to 15, wherein athickness of the second panel (2) is smaller at the panel edge (12) thanin a visible part of the second panel (2) which is visible in a lockedposition of the first (1) and the second (2) panel.

17. The set of panels as in any of embodiments 12 to 16, wherein adistance between a lower edge side (22 a) and a parallel upper edge side(22 b) of the panel edge (12) is smaller than a distance between a lowerside (2 a) and a parallel upper side (2 b), the lower and upper edgesides (22 a, 22 b) being located closer to a side edge (2 c) of thesecond panel (2) than the lower and upper sides (2 a, 2 b).

18. The set of panels as in embodiment 17, wherein the insertion groove(4) is provided in said lower edge side (22 a) or in said upper edgeside (22 b) of the panel edge (12).

19. A set of panels (1,2) comprising a first (1) and a second panel (2),a panel edge (12) of the second panel (2) being insertable into a coregroove (6) of the first panel (1) to obtain a mechanical connectionbetween the first and the second panel, the panel edge (12) beinginsertable into the core groove (6) by an essentially linear relativedisplacement of the first and second panel when the first and secondpanel are arranged essentially in the same plane (MP-1)

-   -   said panel edge (12) comprising a separate and flexible tongue        (3) and said core groove (6) comprising a tongue groove (5), or        said panel edge (12) comprising a tongue groove (5) and said        core groove (6) comprising a separate and flexible tongue (3),    -   wherein the separate and flexible tongue (3) is insertable into        the tongue groove (5) for connecting said panels to each other        in a first direction, which is parallel to a main plane (MP-1)        of the first panel,    -   wherein the panel edge (12) of the second panel (2) is        configured to cooperate with the core groove (6) of the first        panel (1) for connecting said panels to each other in a second        direction, which is perpendicular to the main plane (MP-1) of        the panels (1, 2),    -   wherein a longitudinal direction of the separate and flexible        tongue (3) extends parallel with said panel edge (12) and/or        core groove (6), and    -   wherein the separate and flexible tongue (3) is arranged in an        insertion groove (4), said separate and flexible tongue (3)        being displaceable inwardly towards a bottom of the insertion        groove (4) and outwardly into the tongue groove (5) during a        locking of the first and second panel,    -   characterized in that the separate and flexible tongue (3)        comprises a guiding protrusion (10) at a short edge of the        separate and flexible tongue (3), and that the guiding        protrusion (10) is configured such that its shape changes during        the locking and/or unlocking of the first and second panel.

20. The set of panels as in embodiment 19, wherein the guidingprotrusion (10) is further configured to be in contact with an innerpart of the insertion groove (4) during the locking.

21. The set of panels as in any of embodiments 19 to 20, wherein theguiding protrusion (10) is curve shaped and configured to guide a rodshaped tool (9) into the tongue groove (5) when the rod shaped tool (9)is inserted into the insertion groove (4).

22. The set of panels as in any of embodiments 19 to 21, wherein the rodshaped tool (9) comprises an essentially round cross section.

1. (canceled)
 2. A set of panels comprising a first panel and a secondpanel, a panel edge of the second panel being insertable into a coregroove of the first panel to obtain a mechanical connection between thefirst panel and the second panel, the panel edge being insertable intothe core groove by an essentially linear relative displacement of thefirst panel and second panel when the first panel and the second panelare arranged essentially perpendicularly to each other, said panel edgecomprising a separate and flexible tongue and said core groovecomprising a tongue groove, or said panel edge comprising a tonguegroove and said core groove comprising a separate and flexible tongue,wherein the separate and flexible tongue is insertable into the tonguegroove for connecting said panels to each other in a first direction,which is perpendicular to a main plane of the first panel, wherein thepanel edge of the second panel is configured to cooperate with the coregroove of the first panel for connecting said panels to each other in asecond direction, which is perpendicular to a main plane of the secondpanel, wherein a longitudinal direction of the separate and flexibletongue extends parallel with said panel edge and/or core groove, whereinthe separate and flexible tongue is arranged in an insertion groove,said separate and flexible tongue being displaceable inwardly towards abottom of the insertion groove and outwardly into the tongue grooveduring a locking of the first and second panel, and wherein the separateand flexible tongue comprises a guiding protrusion at a short edge ofthe separate and flexible tongue.
 3. The set of panels as claimed inclaim 2, wherein the guiding protrusion comprises at least one straightportion.
 4. The set of panels as claimed in claim 3, wherein, as seenfrom a top view, each straight portion is inclined with respect to alongitudinal direction of the tongue.
 5. The set of panels as claimed inclaim 2, wherein the guiding protrusion comprises at least two straightportions.
 6. The set of panels as claimed in claim 5, wherein thestraight portions are juxtaposed.
 7. The set of panels as claimed inclaim 5, wherein angles with respect to the longitudinal direction ofthe separate and flexible tongue are different between the differentstraight portions.
 8. The set of panels as claimed in claim 7, whereinthe angle increases by each straight portion towards the tip of theguiding protrusion.
 9. The set of panels as claimed claim 2, wherein theguiding protrusion is curve shaped.
 10. The set of panels as claimed inclaim 2, wherein the guiding protrusion is configured such that itsshape changes during the locking and/or unlocking of the first andsecond panel.
 11. The set of panels as claimed in claim 2, wherein theguiding protrusion is further configured to be in contact with an innerpart of the insertion groove during the locking.
 12. The set of panelsas claimed in claim 2, wherein there is a space between an inner part ofthe insertion groove and the guiding protrusion in a locked position ofthe first panel and the second panel.
 13. The set of panels as claimedclaim 2, wherein the guiding protrusion is configured to guide a rodshaped tool into the tongue groove when the rod shaped tool is insertedinto the insertion groove.
 14. The set of panels as claimed in claim 13,wherein the rod shaped tool comprises an essentially round crosssection.
 15. The set of panels as claimed in claim 2, wherein theseparate and flexible tongue comprises several flexible protrusionsextending in the length direction of the tongue.
 16. The set of panelsas claimed in claim 2, wherein, when said panel edge comprises thetongue groove and said core groove comprises the separate and flexibletongue, said tongue groove is arranged in a lower side or in an upperside of the second panel.
 17. The set of panels as claimed in claim 2,wherein, when said panel edge comprises the tongue groove and said coregroove comprises the separate and flexible tongue, said insertion grooveis formed in said core groove of the first panel.
 18. The set of panelsaccording to claim 17, wherein said insertion groove is arranged in aside wall of said core groove.